A bore-hole jet device is known that comprises a packer provided with a central channel and a jet pump which body is provided with an active nozzle and a mixing chamber with a diffuser as well as a channel for supplying a working medium and a channel for supplying a fluid pumped out of a well, the packer and the pump being arranged on a pipe string, the jet pump body being also provided with a pass channel with the possibility of installing replaceable functional inserts and a sealing unit therein (see, RU Patent No. 2176336 C 1, F04F 5/02, Nov. 27, 2001).
The same patent teaches a method for operating a bore-hole jet device, including arranging the jet pump on a flow string in a well, pumping a chemical agent via the flow string into a formation and subsequently pumping reaction products out of the formation, initially a blocking insert with a pass channel being installed into the pass channel made in the jet pump body, then the blocking insert being replaced with a depression insert and after that a working medium being supplied via the flow string into the jet pump nozzle, thus creating an adjustable bottom-hole pressure in the under packer area and securing the possibility of draining the formation and carrying out other maintenance works.
This bore-hole jet device enables to treat a formation below the level of the jet pump in a well, including creation a pressure differential between the areas above and below the sealing unit. However, the possibilities of this bore-hole jet device are not used in full because a big timetable is required for replacement of inserts, which is often greater than an estimated time of reactions between an acid solution and minerals of a producing formation.
The closest to the claimed device as a subject of the invention in respect of the technical essence and the achieved effect is a bore-hole jet device comprising a packer with a central channel and a jet pump with an active nozzle, a mixing chamber and a pass channel having a seat for installing a sealing unit with an axial channel, which are arranged on a flow string, the device being provided with a transmitter and a receiver-transformer of physical fields, which are arranged in the under-packer area on the side where a fluid pumped out of a well enters the jet pump and are mounted on a logging cable passing through the axial channel of the sealing unit (see, RU Patent No. 2121610, F04F 5/02, Nov. 10, 1998).
The same patent teaches a method for operating the bore-hole jet device, including arranging a jet pump with a pass channel and a packer on a flow string, lowering the assembly into a well, releasing the packer and creating a required depression in the under-packer area by pumping a fluid out of the under-packer area with the use of the jet pump.
This bore-hole jet device and the method for operating it enable to carry out various production operations in a well below the level of the jet pump, including those carried out after reducing a pressure differential between the areas above and below the sealing unit. However, this device does not enable using its possibilities in full, since it allows to carry out surveys of producing rocks only in well bores that are nearly vertical, thus narrowing the applications of the claimed method and the bore-hole jet device proposed for implementing it. Moreover, a rather labor-consuming operation on releasing the packer and subsequently installing it in a new place is, as a rule, required for rearranging the jet pump, which increases the time necessary for carrying out full-scale surveys.